Whole grain products are known to be rich in dietary fiber and other nutrients. Although many health benefits are associated with the consumption of whole grain products, many consumers avoid such products due to the relatively unpopular bitter taste and color associated with whole-wheat flours. This is especially true of children, who can be particularly selective in food choices.
It is generally believed that the presence of bran is a major cause of the taste and color problems associated with whole-wheat flours. Bitter flavors in bran and bran's dark color affect flours' appeal. For example, bran contains phenolic compounds, which may be responsible for the bitter and astringent taste. Certain phenolic compounds, such as tannins, can impart a brown or even grayish color to flour, particularly flours made from red wheat.
Thus, conventional processes used to produce non-whole wheat or white products remove as much bran as possible during milling, although thereby also removing a key nutritional component of the kernel. Specifically, bran not only contains fiber, but other healthy components that are known to be useful in preventing cancer, such as colon cancer.
Recent attempts to overcome these problems of bran's bitter flavor and dark color include use of specially milled and fractionated more bland white wheat or white wheat bran rather than more highly flavored and colored red wheat in an attempt to mask or reduce bran's bitter taste. (See, for example, commonly assigned U.S. Ser. No. 09/512,855 entitled “MILLING HARD WHITE WHEAT”, filed Feb. 25, 2000 by L. E. Metzger et al., which is incorporated herein by reference).
However, since most wheat grown in the North America is of the red wheat varieties, another approach is to bleach wheat kernels especially red wheat with hydrogen peroxide and thereafter to mill the bleached grains to produce whole grain flours of reduced bitter flavor and of lighted color and thus improved appearance (see, for example, commonly assigned U.S. Ser. No. 09/392,699 entitled BLEACHED GRAIN AND GRAIN PRODUCTS AND METHODS OF PREPARATION filed Sep. 9, 1999 by L. E. Metzger, which is incorporated herein by reference).
Rather than the bleaching whole grain kernel, recent attempts also include bleaching isolated bran per se (see, for example, U.S. Ser. No. 09/663,914 entitled “BLEACHED BRAN AND BRAN PRODUCTS AND METHODS OF PREPARATION” filed Sep. 18, 2000 by A. Monsalve-González and L. E. Metzger et al., which is incorporated herein by reference).
Thus, there is a continuing need for whole wheat flours that can be used to provide finished whole wheat products that look and taste as good as those made with “regular” white flour. Also, there is a continuing need for bran products that are useful for addition to regular white or patent flour for the purpose of providing whole grain flours that are comparable to patent or white flours in taste, appearance and baking qualities, notwithstanding the presence of added bran in the flours.
The present invention provides further improvements in the provision of bran and bran containing products having improved flavor and appearance. In particular, the present invention provides further improvements in those methods of bleaching bran as are described in U.S. Ser. No. 09/663,914. While useful and effective, the methods therein described involve a wet treatment of bran with powerful bleaching agents such as hydrogen peroxide. The invention therein also involves techniques for maximizing the effectiveness of the relatively expensive hydrogen peroxide bleaching agent. In the present invention, an alternate bran treatment technique is described. The present invention resides in important part in the realization that substantial improvements in flavor of bran can be obtained by treatment to reduce a particular flavor constituent, ferulic acid, that is present at concentrations ranging only from about 20-50 ppm (parts per million). The present invention thus involves a milder oxygenation treatment of bran to oxidize these low concentrations of particular flavor constituent thereby substantially reducing the complexity and cost of bran treatment and also minimization of any detrimental effects of bran treatment. The present invention also is dry process and thus does not require an expensive post treatment drying step.